chain reaction

noun

1

a

: a series of events so related to each other that each one initiates the next

b

: a number of events triggered by the same initial event

2

: a self-sustaining chemical or nuclear reaction yielding energy or products that cause further reactions of the same kind

chain-react

ˈchān-rē-ˈakt 

intransitive verb

Examples of chain reaction in a Sentence

Increased oil prices could trigger a chain reaction in the economy.

Recent Examples on the Web

Sepsis is a life-threatening medical emergency that happens when an underlying infection triggers a chain reaction throughout the body. —Alyce Collins, MSNBC Newsweek, 31 May 2025

Moreover, although this plan could indeed have a very minimal effect on the sun’s fusion process, the risks of creating a concentrated debris field in certain regions of space or inadvertently triggering an unwanted chain reaction would remain. —Aaron Shattuck, Scientific American, 20 May 2025

The heat causes the cell to vent flammable gas, which can ignite and catch fire, which can cause a chain reaction. —Elizabeth Weise, USA Today, 10 June 2025

Cabrera’s injury seemed to send the chain reaction of landing Chisholm back at third. —Larry Fleisher, Forbes.com, 4 June 2025

Word History

First Known Use

1892, in the meaning defined at sense 1a

Rhymes for chain reaction

• abstraction
• attraction
• compaction
• contraction
• detraction
• diffraction
• distraction
• exaction
• extraction
• impaction
• inaction
• infraction

Kids Definition

chain reaction

noun

1

: a series of events so related to each other that each one sets the next one going

2

: a chemical or nuclear reaction producing energy or products that cause further reactions of the same kind

Medical Definition

chain reaction

noun

: a self-sustaining chemical or nuclear reaction yielding energy or products that cause further reactions of the same kind